This invention relates to a heat exchanger, particularly a refrigerant evaporator, comprised of several hollow bodies connected with one another which are arranged parallel to each other but spaced apart from one another, with a plurality of ribs beings inserted between said hollow bodies in order to increase the heat exchange surface.
Heat exchangers of this type are known as tray evaporators. The hollow bodies in tray evaporators generally comprise two flat saucer-type trays whose edges are placed against one another and are tightly soldered together at these edges. This construction has the disadvantage that relatively large surfaces must be soldered together so that the manufacturing expenses, because of the tolerances that must be maintained for the half-shells to be placed together, and also because of the large surface to be soldered, are considerable. In addition, a relatively high proportion of rejects cannot be avoided.
An objective of the present invention is to avoid this disadvantage while providing a heat exchanger that is simpler to produce.
This and other objectives are achieved by the present invention, in a heat exchanger of the initially mentioned type, by providing it with hollow bodies arranged parallel to and separate from one another. A plurality of ribs are disposed between adjacent hollow bodies, and connecting means fluidly connect adjacent hollow bodies. The connecting means include connecting openings which extend transversely in the longitudinal extent of the hollow bodies.
In a preferred embodiment of the present invention, the hollow bodies are flat tubes which have connecting openings extending transversely to their longitudinal extent in both of their end areas.
By the above developments, the hollow bodies no longer have to be soldered over their whole length. A soldering in the area of the connecting openings and possibly at the closed ends is sufficient. Narrow tolerances do not have to be maintained in the manufacturing of such heat exchangers.
Preferred embodiments of simple manufacture are obtained when the ends of the flat tubes are closed by inserted caps. This takes place by a pressing-in and subsequent soldering or by an alternative sealing means according to certain preferred embodiments of the invention. However, the flat tubes can also be closed very easily by a squeezing-together of their free tube ends, and after the free tube ends are squeezed flat, may be sealed by a fold that can be soldered tight in a simple manner according to certain preferred embodiments. The additional fitting of a sealing strip onto the squeezed-together tube ends is also contemplated according to certain preferred embodiments of the invention.
Certain preferred embodiments provide tube sockets which may be inserted tightly into the connecting openings in a simple manner. The tube sockets are preferably provided, for example, with two stop collars so that they may also serve as an assembling aid for the fitting-together of the flat tubes and hold these away from one another. The heat exchange ribs are preferably inserted along with the tube sockets, so that the subsequent soldering process is easy to carry out.
It has proven to be advantageous according to certain preferred embodiments contemplated by the invention to provide the tube sockets with oval cross-sections and have their narrower projected surfaces aligned in the flow-through direction of the heat exchange agent. As a result, the air-flow resistance through the heat exchanger can be reduced.
Finally, in certain preferred embodiments, the connecting openings may also be developed as openings in an expanded part of the tube wall itself, in which case this part of the tube wall is placed directly against a corresponding part of the adjacent tube and is fluidly connected with it, by soldering, for example. For these embodiments, additional tube sockets are not required. The distance between the flat tubes is maintained by means of the expanded part.
Further objects, features, and advantages of the present invention will become more apparent from the following description when taken with the accompanying drawings, which show for purposes of illustration only, an embodiment constructed in accordance with the present invention.